I was just wondering what most folks are getting for normal cruise speeds with the stock setup and with and with the 180 c/s setup. Some one mentioned that their experience with the straight tail version and the 180 c/s they could not cruise over 125mph???????
KenW

Ken, I have a 1961 175-B with 180 and c/s prop and at 2350/23hg I cruise at 115 kias.
lenny

KEN I SHOULD BE ABLE TO GIVE YOU THE NUMBER ON BOTH THE GO-300 AND THE IO-360A1B6. MY OLD PARTNERS JUST PURCHASE A BRAND NEW PROP. ON THE GO-300 AND I SHOULD GET MY C OF A HOPEFULLY NEXT WEEK SO I WILL KNOW THE NUMBER ON MY STOOTS AVIATION STC 200HP CONVERSION

Thanks guys this is good info, hopefully a few more inputs and i can get an idea of real cruise speeds to target for.
Ken
ps. Norman i have about 50hrs on the hat and i just love it.

Am still at 0 hrs, hope it will change very soon

This depends on loading, but I have the 1960 175a, w/ GO 300C and cruise at 2900-3000 rpm is always around 135 mph indicated. 3050 to 3100 rpm is around 140mph indicated. Hope this helps.

Bob

1959 GO-300A, running 3,000 rpm around 3-4,000 msl, I average 117kt/135 mph, this averaged on opposite direction gps groundspeeds upwind and downwind.
Remember on the fixed prop, there are more than one approved pitch profiles that will affect cruise speeds vs climb performance.

Hi Bob:

I have a 59 175 w/ GO300C, and I love it too!

What rate of burn are you getting at 3000 - 3050 rpm?

Thanks,

Carl Kress
N7546M

I have a '58 with the 180hp C/S conversion. I average about 110ktas running 21" and 2350 RPM around 7,500 feet. I have also found that climbing higher doesn't change the ground speed much but does reduce fuel burn a bit.

I am flying a 1958 175 with the straight tail and the GO-300 with an 80 inch fixed pitch prop.
She flies at 115/118mph at 2800rpms and burns 8 gallons per hour at 4500 in feet altitude.
At 3000 rpms she burns 9.5gallons per hour and crusies at 125/128mph.

For ten mph and only 1.5 more fuel, I would fly the 3000 RPM. Your engine will like it better.
Flying at too low of an RPM is not good for a GO300.

I agree with Clay, for the minimal amount of fuel, the higher rpm is much better for the engine, and it gives you a little more speed
lenny rogers

I fly it at 3200 rpm all the time the engine loves it . Dont lug it. but then I live at 7000 ft.. 119 kt cruse lean of peak.

I flew my 59 straight tail, GO300A, 500 hours or so, cruise at 3000 rpm at 6500' usually indicated 110kts. Average fuel burn for the whole 500 hrs was 9.5 GPH. Really smooth at that rpm. Good engine, needed more power to get out of the ranch!

You need to see if there is an STC for a JATO unit for the 175. LOL

Before starting the 0-470 conversion we would get around 135mph at 3000rpm with about 10gph fuel burn.
The climb performance was extremely impressive even with a load.

With the IO-360A1B6 on floats and gross weight or less am getting 115-120 mph on 11.4 gal approx. /2000'-3000' fts leaning just a bit, the engine is still new so i keep it 100 degres less than lean peak the combi of airframe and power is amazing.

Norman

PERFORMANCE WITH THE FLOATS AT GROSS WEIGHT GOES LIKE THIS: 118-120 MPH AT 24 MPG /2400 RPM C/S , FUEL BURN 10.5 GPH,FULL POWER, 122 MPG@ 13 GPH
CLIMB BEST SPEED 75 MPH AND 800' VSI
OBSTACLE CLEARANCE SPEED 63 MPH AND 650' VSI
STALL SPEED CLEAN CONFIGURATION 50 MPH
STALL SPEED FULL FLAP 40, 40-42 MPH (CLEAN STALL) NO SUPRISE I HAVE THE HORTON STOL.
WEATHER: SUNNY 26 CELCIUS (85F) ALTITUDE (1000'-2000')

NORMAN